King Mongkut (Rama IV) was born in 1804 and reigned from 1851 to 1868. His reign lasted 17 years and marked a turning point in the history of Siam. Surrounded by the colonial expansion of Western powers, the King understood that Siam needed to adapt to survive. During his time on the throne, he worked to move Siam from a traditional kingdom towards a modern, internationally recognised state.
One of his main policies was to develop diplomatic relations with many countries, including Britain, the United States, France, Denmark, Portugal, Germany, the Netherlands and Italy. By balancing these relationships, he hoped to preserve Siam’s independence. He also revised trade agreements to make them easier for Western merchants and introduced new court etiquette: foreign envoys were no longer required to crawl in the royal presence, and Western-style audiences became normal.
His interest in foreign knowledge led him to study English, Latin, mathematics, astronomy, history, archaeology and the sciences. He also supported the printing of books and encouraged reforms that allowed ordinary people to free themselves from bonded service and earn their own living. King Mongkut paid great attention to infrastructure, particularly in transport. He ordered the building of the first modern roads in Siam, including Charoen Krung, Bamrung Muang, Fueang Nakhon and Silom. The first of these, Charoen Krung Road, came about after complaints from Europeans living in Bangkok, who said they had no roads for riding horses or taking leisure walks as they did in Europe.
The King appointed Chao Phraya Si Suriyawong (Chuang Bunnag) to oversee the work, and Henry Alabaster, an English adviser, to survey and design the road. It followed a Western style, with a slightly raised centre and drainage ditches on both sides. This road later became a model for expanding the network outwards from the old city into new areas such as Yan Nawa, Bang Kho Laem and Dao Khanong. Alongside the building of roads, many new canals were dug to make transport by water faster and easier.
Another modernising achievement of King Mongkut was the introduction of standardised time. Before this, people in Siam measured time by natural signs such as tides, moon phases and seasons. The King introduced the “tum–mong” system, which used the sound of drums at night and gongs during the day, but this method was still imprecise and unsuitable for a city becoming more international. To modernise timekeeping, he ordered the construction of the Phra Thinang Phuwadon Thasana, or Royal Clock Tower, within the Grand Palace. This building became the first public clock tower in Siam, providing a shared time standard for the capital. It improved trade, communication and transport by making schedules more accurate and reliable.
King Mongkut was deeply interested in science, especially astronomy. He was known for accurately predicting a solar eclipse using modern calculations. His scientific outlook combined with traditional Thai astrology influenced many of his innovations, including the creation of the clock tower. During his reign, the influence of Western learning, technology and cultural practices grew significantly in Siam. The 17 years of his leadership are now seen as the start of a modernising movement that continued in the reigns of later kings. King Mongkut left behind a legacy of openness to new knowledge, diplomacy, scientific learning and infrastructure that helped prepare Siam for a new era.
